Variables in C programming

A variable is a name given to a storage area that the program can manipulate. Every variable has a specific type to fix the size and layout of the memory. A variable may be some letters , digits and underscore 

character.

Basic variable types:

char     Typically a single octet(one byte). This is an integer type.

int        The most natural size of integer for the machine.

float     A single-precision floating point value.

double A double-precision floating point value.

void     Represents the absence of type.

Example

#include <stdio.h>

// Variable declaration:

extern int a, b;

extern int c;

extern float f;

int main ()

{

  /* variable definition: */

  int a, b;

  int c;

  float f;

  /* actual initialization */

  a = 10;

  b = 20;

 

  c = a + b;

  printf("value of c : %d \n", c);

  f = 70.0/3.0;

  printf("value of f : %f \n", f);

  return 0;

}